1. Field of the Invention
The present invention relates to the field of fuel gauges monitoring the state of charge of rechargeable batteries.
2. Prior Art
In order to meet the market demand to design a very thin Tablet or notebook computer, a battery pack may need to mix cells of different capacities in series or parallel to fit in a particular ID design. For example, a high capacity battery cell may need to be in series with a low capacity cell in the battery pack. When a charger is applied to this battery pack, the lower capacity cell would normally reach full (fully charged) faster than the higher capacity cell. When the system discharges the pack, if both cells started from the same state of charge, the lower capacity cell would normally reach empty (minimum state of charge) faster than the higher capacity cell. Thus for improved battery and notebook form-factor, notebook makers would like to mix and match different sized cells. This presents challenges both for power management and fuel gauging.